1. Technical Field of the Invention
The invention relates to a method for producing a superstructure provided with artificial teeth, which superstructure is fitted on at least one implant, which is provided in the oral cavity of a person and has to be fixed in the bone of a lower or an upper jaw, an aligning plate with at least one aperture being produced for the purpose of drilling a hole in the bone through said aperture, in order to fit the abovementioned implant.
2. Prior Art
The method used according to the prior art for producing such a superstructure is very laborious and protracted for a patient. In a first step, a wax model of a dental prosthesis is made using an impression that is taken of the patient's jaw. A replica of this wax model is then prepared in synthetic resin, in which replica openings are already provided, corresponding to a possible position for the implants, for the purpose of drilling holes in the jaw. A so-called CT scan then has to be made of this replica when it has been placed on the corresponding jaw of the patient, in order to determine the anatomical bone structure and the precise location of nerve bundles and blood vessels. In this way it is checked whether the drilling of holes for the implants is possible, taking into account the anatomical structure of the jaw, such as, inter alia, the position of nerve bundles or blood vessels present there. If it is found that the proposed position of the implants is unsuitable because, for example, nerve bundles or blood vessels would be touched during the drilling of holes, a new or an adapted model has to be produced.
In a subsequent step, an aligning plate is then produced on the basis of the abovementioned replica, and the implants are placed in position. When these implants have been placed and the gums and the bone have healed after this surgical procedure, a number of impressions of the jaw together with the implants are taken, in order to produce a provisional model, i.e. a wax model, of the superstructure. This provisional model then has to be fitted on the patient If the provisional model is satisfactory, the final superstructure is produced on the basis of this provisional model.
In a variant of the above method, the abovementioned first step is to make a CT scan of the jaw on which the superstructure is to be fixed, and an aligning plate is produced directly, on the basis of the electronic information from this CT scan. The superstructure is then further produced according to the technique described above.
Owing to the different steps required in the case of these processes, a patient generally undergoes six months of treatment before a final superstructure is fitted.
Another method according to the prior art makes use of prefabricated superstructures. However, a disadvantage of this method is that for fitting of the superstructure part of the bone of the upper jaw or of the lower jaw has to be removed Furthermore, the prostheses placed in this way are not adapted to the individual shape of a person's jaw.